Coupled activity-current fluctuations in open quantum systems under strong symmetries
Strong symmetries in open quantum systems lead to broken ergodicity and the emergence of multiple degenerate steady states. From a quantum jump (trajectory) perspective, the appearance of multiple steady states is related to underlying dynamical phase transitions (DPTs) at the fluctuating level, lea...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2021-01-01
|
| Series: | New Journal of Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1367-2630/ac0f19 |
| _version_ | 1797750136292507648 |
|---|---|
| author | D Manzano M A Martínez-García P I Hurtado |
| author_facet | D Manzano M A Martínez-García P I Hurtado |
| author_sort | D Manzano |
| collection | DOAJ |
| description | Strong symmetries in open quantum systems lead to broken ergodicity and the emergence of multiple degenerate steady states. From a quantum jump (trajectory) perspective, the appearance of multiple steady states is related to underlying dynamical phase transitions (DPTs) at the fluctuating level, leading to a dynamical coexistence of different transport channels classified by symmetry. In this paper we investigate how strong symmetries affect both the transport properties and the activity patterns of a particular class of Markovian open quantum system, a three-qubit model under the action of a magnetic field and in contact with a thermal bath. We find a pair of twin DPTs in exciton current statistics, induced by the strong symmetry and related by time reversibility, where a zero-current exchange-antisymmetric phase coexists with a symmetric phase of negative exciton current. On the other hand, the activity statistics exhibits a single DPT where the symmetric and antisymmetric phases of different but nonzero activities dynamically coexists. Interestingly, the maximum current and maximum activity phases do not coincide for this three-qubits system. We also investigate how symmetries are reflected in the joint large deviation statistics of the activity and the current, a central issue in the characterization of the complex quantum jump dynamics. The presence of a strong symmetry under nonequilibrium conditions implies non-analyticities in the dynamical free energy in the dual activity-current plane (or equivalently in the joint activity-current large deviation function), including an activity-driven current lockdown phase for activities below some critical threshold. Remarkably, the DPT predicted around the steady state and its Gallavotti–Cohen twin dual are extended into lines of first-order DPTs in the current-activity plane, with a nontrivial structure which depends on the transport and activity properties of each of the symmetry phases. Finally, we also study the effect of a symmetry-breaking, ergodicity-restoring dephasing channel on the coupled activity-current statistics for this model. Interestingly, we observe that while this dephasing noise destroys the symmetry-induced DPTs, the underlying topological symmetry leaves a dynamical fingerprint in the form of an intermittent, bursty on/off dynamics between the different symmetry sectors. |
| first_indexed | 2024-03-12T16:29:20Z |
| format | Article |
| id | doaj.art-45bb977832b34c9a9f540a399a40bddb |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:29:20Z |
| publishDate | 2021-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-45bb977832b34c9a9f540a399a40bddb2023-08-08T15:35:04ZengIOP PublishingNew Journal of Physics1367-26302021-01-0123707304410.1088/1367-2630/ac0f19Coupled activity-current fluctuations in open quantum systems under strong symmetriesD Manzano0https://orcid.org/0000-0001-9241-5884M A Martínez-García1P I Hurtado2https://orcid.org/0000-0003-2196-8988Departamento de Electromagnetismo y Física de la Materia, Universidad de Granada , 18010 Granada, Spain; Institute Carlos I for Theoretical and Computational Physics, Universidad de Granada , 18010 Granada, SpainDepartamento de Electromagnetismo y Física de la Materia, Universidad de Granada , 18010 Granada, SpainDepartamento de Electromagnetismo y Física de la Materia, Universidad de Granada , 18010 Granada, Spain; Institute Carlos I for Theoretical and Computational Physics, Universidad de Granada , 18010 Granada, SpainStrong symmetries in open quantum systems lead to broken ergodicity and the emergence of multiple degenerate steady states. From a quantum jump (trajectory) perspective, the appearance of multiple steady states is related to underlying dynamical phase transitions (DPTs) at the fluctuating level, leading to a dynamical coexistence of different transport channels classified by symmetry. In this paper we investigate how strong symmetries affect both the transport properties and the activity patterns of a particular class of Markovian open quantum system, a three-qubit model under the action of a magnetic field and in contact with a thermal bath. We find a pair of twin DPTs in exciton current statistics, induced by the strong symmetry and related by time reversibility, where a zero-current exchange-antisymmetric phase coexists with a symmetric phase of negative exciton current. On the other hand, the activity statistics exhibits a single DPT where the symmetric and antisymmetric phases of different but nonzero activities dynamically coexists. Interestingly, the maximum current and maximum activity phases do not coincide for this three-qubits system. We also investigate how symmetries are reflected in the joint large deviation statistics of the activity and the current, a central issue in the characterization of the complex quantum jump dynamics. The presence of a strong symmetry under nonequilibrium conditions implies non-analyticities in the dynamical free energy in the dual activity-current plane (or equivalently in the joint activity-current large deviation function), including an activity-driven current lockdown phase for activities below some critical threshold. Remarkably, the DPT predicted around the steady state and its Gallavotti–Cohen twin dual are extended into lines of first-order DPTs in the current-activity plane, with a nontrivial structure which depends on the transport and activity properties of each of the symmetry phases. Finally, we also study the effect of a symmetry-breaking, ergodicity-restoring dephasing channel on the coupled activity-current statistics for this model. Interestingly, we observe that while this dephasing noise destroys the symmetry-induced DPTs, the underlying topological symmetry leaves a dynamical fingerprint in the form of an intermittent, bursty on/off dynamics between the different symmetry sectors.https://doi.org/10.1088/1367-2630/ac0f19fluctuationsspinslarge deviationsnon-equilibriumquantum open systems |
| spellingShingle | D Manzano M A Martínez-García P I Hurtado Coupled activity-current fluctuations in open quantum systems under strong symmetries New Journal of Physics fluctuations spins large deviations non-equilibrium quantum open systems |
| title | Coupled activity-current fluctuations in open quantum systems under strong symmetries |
| title_full | Coupled activity-current fluctuations in open quantum systems under strong symmetries |
| title_fullStr | Coupled activity-current fluctuations in open quantum systems under strong symmetries |
| title_full_unstemmed | Coupled activity-current fluctuations in open quantum systems under strong symmetries |
| title_short | Coupled activity-current fluctuations in open quantum systems under strong symmetries |
| title_sort | coupled activity current fluctuations in open quantum systems under strong symmetries |
| topic | fluctuations spins large deviations non-equilibrium quantum open systems |
| url | https://doi.org/10.1088/1367-2630/ac0f19 |
| work_keys_str_mv | AT dmanzano coupledactivitycurrentfluctuationsinopenquantumsystemsunderstrongsymmetries AT mamartinezgarcia coupledactivitycurrentfluctuationsinopenquantumsystemsunderstrongsymmetries AT pihurtado coupledactivitycurrentfluctuationsinopenquantumsystemsunderstrongsymmetries |